const fp = require('lodash/fp')
const { Maybe, Container } = require('./support')

let maybe = Maybe.of([5, 6, 1])
console.log(nae);

//练习1



function add (x) {
    return fp.add(x, 1)
}
let ex1 = () => {
    let result = maybe.map(x => fp.map(add, x))
    return result
}
console.log(ex1())

//练习2
let xs = Container.of(['do', 'ray', 'me', 'fa', 'so', 'la', 'ti', 'do'])
let ex2 = () => {
    return xs
        .map(x => fp.first(x))
}
console.log(ex2());


//练习3
let safeProp = fp.curry(function (x, o) {
    return Maybe.of(o[x])
})
let user = { id: 2, name: 'Albert' }
let ex3 = () => {
    return safeProp('name', user)
            .map(fp.first)
            ._value
        
}
console.log(ex3())


//练习四
let ex4 = (n) => {
   return  Maybe.of(n)
        .map(n=>parseInt(n))
}
console.log(ex4(null))
